The Elvis Influence is a web app that shows how just about any modern artist has been directly or indirectly influenced by the King of Rock and Roll.
Given an artist, The Elvis Influence will follow the chain of influences and band membership back (or forward) to Elvis Presley. The path to Elvis is highlighted by high quality artist imagery. Press the 'listen' button to hear a playlist of the path to Elvis.
The Elvis Influence is online at http://static.echonest.com/insights/elvis/elvisualization.html.
Also included with the app is a graph-oriented visualization for the top 800 or so artists.
It makes use of the Spotify Web API.